In the process of pressure transfer of gas hydrate core samples， the core capture device is the key to realize sample transfer. Core capture is carried out in the core tube， which belongs to the non-visual operation process. At the same time， the core sample and the capture device are in high pressure liquid. The gap between the core liner and the core tube is very small. To ensure the in-situ state of the core sample， there are high requirements for the structural design， accurate positioning， rapid capture and release of the core capture device. According to the capture， drag， positioning and release functions required by the device， the hanging plate self-locking and the contact unlocking mechanisms are designed， and the probe is used to capture the liner. Indoor capture experiment shows that the mechanism can successfully capture and unlock the core. The structure is simple， and the core can be transferred at pressure， which accelerates the research progress on the pressure transfer device of natural gas hydrate.